/**
    * Copyright 2005-2008 the original author or authors.
    *
    * Licensed under the Gnu General Pubic License, Version 2.0 (the
    * "License"); you may not use this file except in compliance with
    * the License. You may obtain a copy of the License at
    *
    *      http://www.opensource.org/licenses/gpl-license.php
    *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
   * See the Gnu General Public License for more details.
   */
  package org.figure8.join.core;
  
  import org.figure8.join.core.setup.BootstrapUtil;
  import org.figure8.join.core.setup.BootstrapManager;
  import org.figure8.join.util.LogUtil;
  
  import org.apache.commons.logging.Log;
  import org.springframework.beans.BeanUtils;
  import org.springframework.beans.BeansException;
  import org.springframework.context.ApplicationContext;
  import org.springframework.web.context.ContextLoader;
  import org.springframework.web.context.WebApplicationContext;
  import org.springframework.web.context.ConfigurableWebApplicationContext;
  import org.springframework.util.StringUtils;
  
  import javax.servlet.ServletContext;
  /**
   * An extension of Spring <code>ContextLoader</code> that always load the
   * Join bootstrap context as parent context.
   * @author <a href="mailto:laurent.broudoux@free.fr">Laurent Broudoux</a>
   * @version $Revision: 1.4 $
   */
  public class ContainerContextLoader extends ContextLoader{
  
     // Static -------------------------------------------------------------------
  
     /** Get a commons logger ... */
     private static final Log log = LogUtil.getLog(ContainerContextLoader.class);
  
     /**
      * Name of servlet context parameter that can specify the extra config location
      * for the root context. This locations may be added to those present in default
      * config location depending on the result of <code>addingExtraConfigLocationAllowed()</code>
      */
     public static final String EXTRA_CONFIG_LOCATION_PARAM = "extraContextConfigLocation";
  
  
     // Constructors -------------------------------------------------------------
  
     /** Creates a new instance of ContainerContextLoader */
     public ContainerContextLoader(){
        super();
     }
  
  
     // Override of ContextLoader ------------------------------------------------
  
     /**
      * Load the parent context for the given servlet context. Always use
      * the Join bootstrap context in this case.
      * @param servletContext Servlet context for whom load parent context
      * @return The Join bootstrap context.
      */
     protected ApplicationContext loadParentContext(ServletContext servletContext) throws BeansException{
        return BootstrapUtil.getBootstrapContext();
     }
  
     /**
      * Instantiate the root WebApplicationContext for this loader, ie a XmlWebApplicationContext.
      * <p>This implementation expects custom contexts to implement
      * ConfigurableWebApplicationContext. Can be overridden in subclasses.
      * @param servletContext current servlet context
      * @param parent the parent ApplicationContext to use, or null if none
      * @throws org.springframework.beans.BeansException if the context couldn't be initialized
      * @return The newly created Join web application context
      */
     protected WebApplicationContext createWebApplicationContext(ServletContext servletContext, ApplicationContext parent)
             throws BeansException{
        // Instanciate the default implementation of app context.
        ConfigurableWebApplicationContext wac = (ConfigurableWebApplicationContext)
                BeanUtils.instantiateClass(DEFAULT_CONTEXT_CLASS);
        // Set its parent and servlet contexts.
        wac.setParent(parent);
        wac.setServletContext(servletContext);
  
        // Set its configuration files location.
        String configLocation = servletContext.getInitParameter(CONFIG_LOCATION_PARAM);
        // Check if some extra configuration files should be added.
        if (addingExtraConfigLocationAllowed()){
           String extraConfigLocation = servletContext.getInitParameter(EXTRA_CONFIG_LOCATION_PARAM);
           if (extraConfigLocation != null && extraConfigLocation.trim().length() > 0)
              configLocation += (ConfigurableWebApplicationContext.CONFIG_LOCATION_DELIMITERS + extraConfigLocation);
        }
        if (configLocation != null){
           wac.setConfigLocations(StringUtils.tokenizeToStringArray(configLocation,
                  ConfigurableWebApplicationContext.CONFIG_LOCATION_DELIMITERS));
       }
       // Refresh and return.
       wac.refresh();
       return wac;
    }
 
 
    // Protected ----------------------------------------------------------------
 
    /**
     * Check if some extra configuration files locations should be added
     * to the default one. This is a hook for subclasses to specifiy their
     * adding criteria. This implementation return true if this context is one
     * the asynchronous side of the application (so that asynchronous applicative
     * services may be started)
     * @return True if we are on asynchronous side of the application, false otherwise.
     */
    protected boolean addingExtraConfigLocationAllowed(){
       BootstrapManager manager = BootstrapUtil.getBootstrapManager();
       // Do not allow initialization if not bootstrapped.
       if (manager == null || !manager.isBootstrapped())
          return false;
       // Check if setup is coherent.
       if (!manager.isSetupComplete())
          log.error("Setup is not yet complete, but trying to load context ?!... - Maybe join.cfg.xml is corrupted ?");
       // Return whether we are on asynchronous side or not.
       return manager.isAsynchronousSide();
    }
 }